ERerichocean·Feb 24, 2025
> There is no way to know what's being passed around without reading the source of the whole chain.
But that's not what a Clojure dev would do.
1) We use Malli [0] (or similar) to check specs and coerce types if needed at every point. Checks can be left on in production (I do), or disable–up to you.
2) If the coercion is difficult, use something like Meander. [1]
3) If even that isn't straightforward and you need actual logic in the loop, use Specter. [2]
4) If you're not sure what going on at intermediate steps, use FlowStorm [3].
5) But you're going to be processing a lot of data you haven't seen before! Use, Malli with test.check [4] and make use of property-based testing with generators.
None of this is "advanced" Clojure, this is bread-and-butter stuff I use every day.
6) Need a Notebook-like experience to get better visualization of
Read the rest
intermediate data? Use Clerk [5].
7) Need special checks on API usage within your codebase? Use clj-kondo [6] with custom linters. They're less than 10 lines each.
Unlike default-mutable languages, or typed, it's safe and easy to use libraries with Clojure and they tend to have very little churn. Total opposite from Python or JavaScript (if you're used to that).
It's almost impossible to give the impression of what it is like to develop with Clojure if you've only ever used languages with static typing, or languages from the Algol family.
Honestly, I hated Clojure's syntax at first BECAUSE I COULDN'T READ IT, and I loathed "structural editing." After 2-3 weeks, I read it just fine and it's hard to remember I ever couldn't do so. Now I like it, and structural editing makes it so easy to change your code, I couldn't live without it at this point.
Basically, all my "fears"/dislikes were unfounded—it was a skill issue on my part, not a problem with Clojure.
[0] https://github.com/metosin/malli
[1] https://github.com/noprompt/meander
[2] https://github.com/redplanetlabs/specter
[3] https://www.flow-storm.org/
[4] https://github.com/clojure/test.check
[5] https://clerk.vision/
[6] https://github.com/clj-kondo/clj-kondo